This invention relates to valves, and more particularly to power-operated valve and pump apparatus for flooding and evacuating sea water from compartments of ships.
Efficient disposal of excess or unwanted water, which leaks or is admitted into waterborne vessels, has historically been a problem of great concern. Sea water can enter a ship's compartments in a "passive" manner, e.g. by leakage or flooding (as disclosed in the U.S. Pat. Nos. 551,473; 706,561; and 1,127,648 to Perkins, Holland and Lake, respectively) or in an "active" manner, e.g., by pumping (as disclosed in the U.S. Pat. Nos. 1,796,200, 3,242,613 to Grieshaver and Schwartz, respectively).
At present the two most widely used methods of water evacuation involve either removal of the water from a compartment by centrifugal pumping, or by sealing a compartment and pumping of compressed air into it to "blow out" the water. There are disadvantages, however, attendant with conventional centrifugal pumping methods which make their use extremely undesirable. These methods require, for example, use of extremely expensive machinery and extensive amounts of interconnecting piping. Related to this is the great loss of energy (power consumption) due to frictional losses in the piping system. And in the "blow out" method, a great amount of non-recoverable heat is generated as a result of the air compression, and the pumped air is heated sufficiently to require extensive insulation of the air pipes. This extra insulation not only increases installation costs, but also adds extra weight and maintenance.